Decreasing the rates of unintended pregnancies, abortions, and teen births isn't rocket science: What works is wide access to contraception, comprehensive sexual health education, and openness about human sexuality instead of shame and judgment. Colorado is the latest state to embrace at least part of that prescription: The state distributed 30,000 contraceptive devices at low or no cost. And they saw teen birth rates fall by 40 percent.

The Colorado program focused on intrauterine devices (IUDs), a highly effective form of birth control that lasts for several years and has a failure rate of less than one percent. That's also one of the methods of birth control religious employers objected to in the Hobby Lobby case — and because of that decision, many women will no longer have affordable access to the most effective way of preventing unwanted pregnancy.

IUDs are the most popular form of reversible contraception worldwide and are both safe and virtually foolproof. But the United States has lowest rate of IUD use of developed countries; our abortion rate is one of the highest. IUDs are less common in the United States in part because an early form of the IUD, the Dalkon Shield, caused serious complications and infections in the 1970s, making both women and doctors wary of the device. Today's IUDs, though, pose no such issues, and women increasingly want them when they're available. The copper IUD is hormone-free, making it a good fit for women who can't take hormonal birth control like the Pill. Even women who have issues with many forms of hormonal birth control report success with Mirena or Skyla IUDs, which emit progesterone to prevent pregnancy. The number of American women using IUDs has more than tripled since 2002.

But cost is a significant barrier: Getting an IUD can exceed $1,000. The Colorado program, called the Colorado Family Planning Initiative and funded by an anonymous donor, was particularly effective because it removed the money roadblock, offering IUDs to low-income women in 68 family planning clinics across the state since 2009. That one program accounted for three-quarters of the decrease in teen births across the state, and counties with the initiative in place saw the teen abortion rate drop by 35 percent. It also saved the state a significant amount of money: For every dollar spent on family planning, the state saved $5.68 in Medicaid costs.

To make IUDs and all contraception more affordable and accessible, which in addition to making it easier for women to prevent unwanted pregnancy also has significant economic and public health benefits (Colorado saved $42.5 million in 2010 alone), the Obama administration required full contraception coverage in its health care law. Anti-abortion groups objected. Even though contraception access has been shown to significantly reduce the abortion rate, there is not a single mainstream "pro-life" group in the United States that supports birth control access. Many of the groups claim that contraception actually causes abortion (it doesn't) and that access to free birth control makes women more likely to have sex (it doesn't). Nevertheless, the religious owners of the for-profit Hobby Lobby craft stores sued over the law requiring them to include contraception in their employee health plans and won in the Supreme Court.

Now, even for-profit companies don't have to include contraception, including the highly effective and very expensive IUD, in their health care plans if they're owned by someone whose religion tells him birth control is wrong.

The Obama administration has been working on a fix, and today Senate Democrats announced that they had drafted a bill to ensure that women get contraception regardless of their employers' beliefs. Unfortunately, it's unlikely that any compromise will placate anti-abortion advocates. Even Colorado's success in decreasing the abortion rate didn't satisfy opponents: a Focus on the Family spokesperson declared, contrary to the evidence, that "access to contraception does not equal fewer unintended pregnancies and fewer abortions."

Ideally, preventing unwanted pregnancy and thereby decreasing the abortion would be something on which pro-lifers and pro-choicers could agree and work together. But so far, the pro-life answer to abortion prevention has been "don't have sex before you're married," a case that's hard to make in a country where 95 percent of people have sex before they're married and where married women terminate pregnancies too.

The good news out of Colorado is one more data point on a long line of positive outcomes from contraception access. It may not convince the most extreme opponents of birth control, but it's another example of why proven effective methods, and not ideology, should dictate public health policy.